Serpentine heating exchangers are well known and typically include at least one flattened, multiple port tube, usually of extruded configuration, bent into a serpentine configuration to have a plurality of parallel runs where fins, generally serpentine fins, extend between adjacent ones of the parallel runs. These serpentine heat exchangers are most typically employed in two phase heating exchange as, for example, in refrigeration systems (including air conditioning systems) wherein a refrigerant passing through the tube changes phase. When used as an evaporator, the refrigerant evaporates from the liquid phase to the gaseous phase and where employed as a condenser or gas cooler, the refrigerant changes from the gaseous phase to or toward the liquid phase. Typical examples are illustrated in U.S. Pat. Nos. 5,368,097 and 5,036,909. Examples may also be seen in Japanese patent document 6-317363 of Nov. 15, 1994 and German patent document DE10049256A1. Reference may also be made to Japanese patent document JP06317363A.
In the German heat exchanger, special flow guiding locations are provided to convey the internal heat transfer medium from a rear cooling branch to a front cooling branch, the guiding configurations being individual tubes into which the ends of two cooling branches or sections constructed from two multiple channel flat tubes communicate. A gaseous heat exchange medium flows through several of the cooling branches arranged one behind the other in the same direction and while the construction works well for its intended purpose, manufacture can be difficult in terms of fitting the components that provide the guiding function to the apparatus.
The heat exchanger shown in U.S. Pat. No. 5,036,909 is intended for use as an evaporator in an air conditioner. This heat exchanger utilizes a separate tube to guide the refrigerant from a cooling branch in the inlet side to two subsequent cooling branches and is supposed to simultaneously serve as a mixing chamber for the equalization of the temperature of the internal heat exchange fluid. Another heat exchanger of this general type is shown in Japanese patent document JP06317363A. Both of these designs also work well for their intended purpose but may be difficult to manufacture for the reasons above stated.
The present invention is intended to overcome one or more of the above problems.